A silicone-type adhesive in the form of a hydrosilylation-curable silicone composition that is cured when it is sandwiched between two sheets of protective film (see Japanese Unexamined Patent Application Publication No. H11-12546) is suitable for adhesively attaching a semiconductor chip to a chip-attaching part, but when the thickness of the sheet is 50 μm or less, and when the roughness on the surface of the chip-attaching part is equal to or greater than 10 μm, the gap-filling capacity of the bonding sheet becomes insufficient for filling the valleys of the microroughness, whereby it becomes impossible to provide sufficient strength of the adhesive connection.
Although a laminated sheet structure composed of a cray-like curable silicone composition layer and a cured silicone layer, or of two clay-like curable silicone composition layers having different speeds of curing (see Japanese Unexamined Patent Application Publication No. 2004-43814), possesses satisfactory gap-filling properties, such properties are still insufficient when the allowable die-attach pressure is limited due to the extreme thinness of film-like stack-package type chips which have been recently developed.
It is an object of the present invention to provide a reactive hot-melt silicone adhesive that demonstrates good gap-filling ability during thermo-compressive bonding to adherends with high surface roughness even with application of low pressures and that provides strong adhesion to the adherend after curing.